[builtins] Add ReturnReceiver builtin

src/builtins/builtins-promise.cc

Index: src/builtins/builtins-promise.cc
diff --git a/src/builtins/builtins-promise.cc b/src/builtins/builtins-promise.cc
index 46f6043bd3c85350d81ea25da6940d0219a4b0ef..e4d8ece5522b16547ed543d95c5b471db6b618f6 100644
--- a/src/builtins/builtins-promise.cc
+++ b/src/builtins/builtins-promise.cc
@@ -991,5 +991,11 @@ TF_BUILTIN(PromiseHandle, PromiseBuiltinsAssembler) {
   }
 }
 
+TF_BUILTIN(PromiseSpeciesGetter, PromiseBuiltinsAssembler) {

[adamk, 2016/12/20 23:03:12]

Seems like we should only need one of these builtins (not one for Promise, one
for RegExp, etc). Maybe put it in builtins-internal.cc?

[caitp, 2016/12/20 23:58:05]

%IteratorPrototype%[@@iterator] can reuse this code, too. 

+  // 1. Return the this value
+  Node* const receiver = Parameter(0);
+  Return(receiver);
+}
+
 }  // namespace internal
 }  // namespace v8